1. Field of the Invention
The present invention relates to a waterproof structure of a casing of a portable electronic device or the like.
2. Description of the Related Art
There are waterproof structures for a portable transmitter each of which holds a peripheral end portion of a waterproof cover between two separate cases, as described in Unexamined Japanese Patent Application KOKAI Publication Nos. H11-288635 and 2004-312621.
There is also a waterproof structure for a weighing machine in which an end portion of a waterproof diaphragm is press fitted in a recessed groove provided at a case, as described in Unexamined Japanese Patent Application KOKAI Publication No. 2003-322556.
If the end portion of the waterproof cover is held by the separate two cases from above and bottom, however, elastic force acts in the vertical (up and down) direction. It is therefore necessary to provide a lot of screws or a lot of hook parts to fix the separate cases.
The end portion of the waterproof diaphragm, if merely press fitted in the recessed groove provided at the case, may come out due to vibration or the like. This impairs the waterproofing capability.